Envelope blank



FIG. 1 is an elevation of the inside portion of an envelope blank showing my new design;

FIG. 2 is a top plan view thereof;

FIG. 3 is a bottom plan view of FIG. 1;

FIG. 4 is a left side elevational view of the envelope blank shown in FIG. 1 in a partially assembled condition;

FIG. 5 is a reduced elevational view of the envelope blank shown in FIG. 1 in a partially assembled condition; and

FIG. 6 is a side view of the envelope blank in a partially folded condition;

FIG. 7 is a reduced elevation of the side opposite disclosed in FIG. 5. 

The ornamental design for an envelope blank, as shown and described. 